TREX is a phase IIIb, multicenter, randomized, controlled clinical study. Subjects will be randomized 1:2 to "monthly" (control arm) or "treat and extend" protocol (comparator arm) respectively. TREX assess the safety, tolerability and efficacy of intravitreal injections (IVT) of 0.5mg ranibizumab given monthly for up to 100 weeks followed by pro re nata (PRN) treatment for 56 weeks compared to a Treat and Extend protocol for 156 weeks in patients with wet age-related macular degeneration (AMD). Subjects treated in a treat and extend protocol receive 3 consecutive IVT 0.5 mg ranibizumab (visits 2, 4 and 5). Starting at week 8, if a subject has achieved a "dry" macula; signs of active exudation have resolved will begin a Treat and Extend protocol (visits lengthened by 2 week intervals every visit a dry macular is maintained). At the beginning of the 104-week endpoint subjects initially randomized to the TREX cohort will transition to PRN re-treatment when there is no exudative disease activity at the 12-week interval.